


Ingredients to Flaunt

by Candlewax



Category: Undertale
Genre: Bara Sans (Undertale), Courtship, Dry Humping, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), F/M, Knotting, Male Masturbation, Mating Cycles/In Heat, Obsessive Sans, Possessive Sans (Undertale), Reader is confused, Reader-Insert, Sans is big boy, Sans wants to help, Seduction, Short Story, undertomb
Language: English
Status: In-Progress
Published: 2019-09-23
Updated: 2020-09-10
Packaged: 2020-10-26 13:34:53
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 7
Words: 17,009
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20743037
Author URL: https://archiveofourown.org/users/Candlewax/pseuds/Candlewax
Summary: Sans truly did not understand much at first.He didn’t understand the sudden absence during your secret nightly visits. He didn’t understand the frequent mood swings you experienced. He didn’t understand how hot your body seemed at times, yet how you weren’t sick. He didn’t understand how loud your soul would beat at times in cold, dead nights.Then it hit him like a brick.Of course!You are in heat!Wait…. That doesn’t make sense. Humans don’t go into heat.





	1. A New Scent

**Author's Note:**

> Chapter One is rushed and I apologize. The next few chapters are gonna be a little lengthy. I wanted to take on the idea that the reader is in heat and not just Sans. He'll be the one helping the reader cause the reader knows next to nothing about heats.

**Summary for the Chapter:**

> Sans discovers a new oddly pleasing smell.

Sans truly did not understand much at first.

He didn’t understand the sudden absence during your secret nightly visits. He didn’t understand the frequent mood swings you experienced. He didn’t understand how hot your body seemed at times, yet how you weren’t sick. He didn’t understand how loud your soul would beat at times in cold, dead nights.

Then it hit him like a brick.

Of course!

You are in heat!

Wait…. That didn’t make sense. Humans don’t go into heat.

The primary thing to find out was how.

How can a human go into heat?

Humans don’t use nearly as much magic as monsters. Hell, most of them never used any of their magic, even going as far as to believing it’s fake.

Sans theorized that since you lived in the underground for oh, so long (seven years to be exact) your soul used the strong, thickly essence of remaining magic in the underground atmosphere to survive long periods of hunger. And since your soul consumed so much magic, it needed a way to dispel.

And it did find a way, heat.

The next to find out is, would your human heat be the same as monster heat? He expected so. Then it’d be greatly easier to take care of your problem. And stars, he hopes your heat wouldn’t endure long.

The last to find out, are you… _home_? Your home?

He knows precisely where you sojourn. In a deep cavern just ways off, by the large door the nice (and rather disturbing) matron previously lived. The way inside held many twisting and turning tunnels, one could get horribly lost and never find a way out.

But you’re clever, You know the tunnels like the back of your hand. One of those tunnels led to your compact little home. Since it was remote from the cold snowy outside, your cove felt completely warm. There was only a thick mattress (provided by sans), multiple lush blankets, four fluffy pillows, a journal, some pencils, and a lantern. It was tall enough for him to crawl around in and for you to stand that the ceiling just scraped past your head by an inch (his back would hunch over if he attempted to stand full height). It was wide enough for three of them to sit snugly but that was about it.

He couldn’t think of another place you could be in, so it was a safe bet to assume you were home.

Sans currently laid in his bedroom bed, eye lights to the ceiling in deep thought. It was night, or what the underground seemed to call night. Night meant everyone who remained in the underground was asleep and quiet. No disturbance outside thus everyone can sleep in peace.

Perfect opportunity to meet you.

He was uncertain you would be at the bridge. Sans twisted over his bed and eyed his bedside clock. He noted the rather late time. Eleven at night. Almost a handful minutes before your secret meetings (he loved those).

You and Sans would meet exactly at eleven-thirty every night. The both of you would usually mess around with the snow, talk in deep conversations, or cook up a new kind of meat (you’re a fantastic cook). Whatever you guys did, he loved it. It didn’t matter, just as long as he was with you. Sometimes those nights would end with you and him cuddled in sound sleep inside your cave or he’d teleport you in his home to slumber together (those nights were the best).

But for the past few days, you asked to end those nights early. And yesterday, you didn’t even show up at all. He was troubled, wondering if you were sick of him.

Then he felt frightened, did something horrible happen to you?

Monsters devour humans. And although monsters could teleport back and forth to the surface to hunt whenever they pleased, they wouldn’t pass up a human hiding amongst their village. That’s why you both met in secret, he was keeping you safe. And you knew this, thankfully remaining to yourself. Well, making an exception for him. Sans was your main source of food income. He brought meat every day. Which reminds him….

If you went into heat, why did your soul still absorb magic?

Sure, he began feeding you just three years ago, but wouldn’t your soul have finished eating? He ended his theory by assuming that your soul continued it’s consumption as a back-up plan, were anything to happen to your food source.

Sans turned over in his bed again. He hoped you were okay. By the singing of your soul, you were at the beginning of your heat. Sans wasn’t worried about other monsters hearing your soul right now. Most didn’t live in the underground anymore.

Plus, he always possessed a natural talent to hear even the most quiet souls in the loudest moments. That’s why he was remarkably good at hunting.

Still, your soul remained _clamorous_.

As far as he knew, there are only four steps to heat.

The first, agitation.

Agitation made a monster (or in this case, you) hide away from the public. They were constantly tired and turned away from food. This step lasted in the span of a few days.

Sans eyed the clock again. Eleven twenty-five. He hummed indecisively. He really wants to see you, even in your most aggressive mood, he wants to see how you’re managing so far. He needed to prepare to help you (if you wanted that is). Making up his mind, Sans speedily shoved his slippers on and teleported away.

He wobbled a little as he landed by his sentry point in his flurry.

Perfect.

As Sans hurried through the snow, he scented a faint, citrine, butterscotch scent intermingled with sweat and tension. His soul responded with interest by pulsing, sending small magic ripples of signal to the female in heat.

You were merely in step one of heat. The smell wouldn’t affect him, only demonstrate interest and exert dominance towards any potential threat. Your smell would only change on step three, where it would send very... explicit signals to his soul.

That wouldn't be for a while.

For now, he dug and kicked a line of snow that dipped down to the dirt and stretched around the outside of the bridge, forming a half-circle. Then he summoned his soul and marked the line with a small spray. It smelled of heavy testosterone, a salty and almost spicy scent. It conveyed messages to any trespasser to **_b__ack off_**. This way, he claimed the territory and the female in heat inside the territory line. Sans couldn't imagine any monster would challenge him for it.

They must have a death wish.

He walked beyond the bridge with his soul out, continuing to mark along the inside of his newly claimed territory, ensuring ownership. He couldn’t wait to see you. It’s only been a day but it’s the most the two of you been apart in two years.

As he arrived at the entrance of your cave, he dispelled his soul back inside his ribcage. He inhaled the now more potent scent of you. He lifted a brow bone.

How the hell did you figure out how to make a scent mark? Scent marks (what Sans just did to the outside of the bridge with his soul) send rather hostile messages. They are claims to possession and usually cause fights amongst monsters. And they are laborious to master. You arranged so almost expertly. Your scent mark perfumed estrogen. Sweet. And a little tangy.

He felt hesitant now. His soul told him to back off and leave you be for a while, scent marks were no joke. But he still longed to see you, so bracing himself, he entered.

He recognized the way into your tiny cave but his soul began to thrum in slight uncertainty. He was a little startled. Even though you were much shorter and more gentle natured, your scent mark told every fiber of his soul to 'go away' and 'don’t mess with me'.

But he continued.

He heard a low growl. Higher pitched than a male would make, but it implied warning. He slowed a bit, stepping lightly.

Then he heard the growl go deep and dull. He kenned you, his soul sending friendly, peaceful waves of vibrations to your soul. Your soul responded with fierce, challenging shocks back.

He didn’t believe this was a solid idea anymore. As he entered your home, he saw a dim, small shadow nestled in blankets and pillows. The figure shifted.

  
It was you, of course. Your hair was knotted horribly, your face dry and drool crusted across your lips. You looked completely disheveled and tired, eyes dull and cloudy.

His soul fluttered.

“(y/n)!” He exclaimed in relief and excitement.

You snorted, slowly rising by your haunches and glaring _hard, _a snarl across your lips. Your delicate fingers curled into claws, ready to strike across his skull.

He found the scene quite hilarious, he just had to snicker. He wasn't afraid anymore, he remembered how small you were compared to him. He dwarfed you by several inches. 

You couldn’t possibly leave any lasting scars on him.

You were so kind and gentle and loving and patient.

Right now though, you looked like you could just about annihilate him. Heats made even the most relaxed host animalistic and impulsive, so he understood your reactions.

“i’m so glad you’re safe.” He sighed. He acknowledged your hazy state of mind, understanding anything must be difficult.

You crept closer and snarled, your soul abandoning the security of your body and whirring to fight. Sans's soul came out with similar buzzes.

  
The souls were challenging each other.

He scoffed. Sans wasn’t afraid, he could handle-

His right leg was yanked forward so swiftly that his skull thunked against the hard dirt underneath. You mounted and pinned him down, growling loudly. 

Sans blinked, dazed over what just happened before your nails slashed across his face. 

He winced. _that hurt! _

He took the liberty to flip both of you over so that he pinned you underneath instead.

“okay, that’s enough-” He didn’t get to finish, your feet stretched up and struck his nasal hole so hard, he let you go. He groaned and clutched his face. 

You returned with two more strikes across his eye sockets with your powerful, rather sharp nails.

Sans yielded and teleported outside your den. His face stung like hell. Yup, that was a mistake.

He eyed the dark, dreary den once more. He’ll check up on you later. Right now, he thinks he needs some bandages.

\---

You groaned as another wave of unadulterated pain spread across your uterus, shaking your inner walls in agony. You writhed around your hand-me-down mattress, wrapped in thick blankets (the only thing bringing you comfort). 

Your entire body felt unusually hot, beads of sweat formed behind your neck, armpits, thighs, forehead and between several folds of your body. You gagged, unsure if you needed to vomit. 

This is nothing like you ever experienced before. For a moment, you thought you ate a rotten rabbit or a diseased deer. Then you began to think it was some form of cancer, a tumor slowly killing you by the seconds.

You counted on the tumor.

\---


	2. Not a Good Idea

**Summary for the Chapter:**

> Sans acts out his morals... kind of.

**Notes for the Chapter:**

> Okay, this isn't a long chapter but I wanted to get this out to you guys. Next chapter, there will be sexual tension and probably some smut.

\---  
You stand victorious, your shoulders raised in triumph. You didn't think you'd win against the looming threat, but you defied defeat. You retreat to your bed, wondering who exactly the threat was (he kind of looked like Sans) everything was blurry and all you wanted to do was shred anyone brave and foolish enough to enter your home. You lay on your bed, planning on sleeping.

You feel as if you awoke from a nightmare. You were no longer overheated and the excruciating pain from before vanished. You did feel a little anxious, you don't know why. You wondered if Sans fared well without you. Did he visit yesterday?

You pull your blanket off of you, wincing as your index finger quivered in injury. You brought your hand over, noticing one of your nails was chipped.

Must've been an accident.  
\---

For the remainder of the day, Sans kept to his usual schedule.

Sleep, hunt, sleep, work, hunt, sleep.

Between his breaks, Sans visited the opening of your den but no further. He regularly left fresh scent marks across his territory’s border. As did you, your unique scent mark always concentrated and pungent inside your cave. He understood that you only left your den for scent marks but didn’t you didn't do much else. After his evening hunt, he tore a large chunk from his newly skinned deer and dropped it outside your den. As daybreak came, and he checked up on you, the flesh he left for you was gone, not a piece left. A swell of pride rose in his ribcage. He additionally left bowls of clean, crisp water out. The water would be gone instantly so Sans would then leave two bowls.

This persisted on for three whole days before he began to worry again. How long would this stage persist?

On the fourth day, as Sans laid out a rabbit and more bowls of water, he took the chance to inhale your scent. Still the same citrine, butterscotch scent with sweat, but the tension was gone and your scent marks were weak and faint.

Sans squinted. Stage two, huh?

At stage two, the pain of the hosts' soul would ebb and instead of a sweaty, hostile being, they were previously, the hosts' behavior goes back to normal. You would be yourself again, but only for a day. Stage two was considered a break since stage one was a pain-inducing introduction.

This also means he'd have to perform a courtship for you in stage three. The thought brought a bright red blush to his skull. He fidgeted with his hoodie strings.

He has to court you, otherwise, your soul would start sending signals across the underground. Sans shook his head and raised his chin. Your heat is his responsibility. He'll have to be the bigger monster.

Sans stood up, rolling his shoulders and preparing his soul for the ancient ritual and proceeded inside.

As he walked along in the tunnels, his soul sent the same, peaceful and friendly vibrations as he did the first day of your heat. This time, your soul sent confused and curious thrums back. As he reached your den, he heard a shuffle of blankets. Then a soft voice spoke.

"Sans?"

Sans wasted no time to teleport.

You cautiously rose up, no longer laying in bed but rather drawing inside your journal. You looked taken aback before smiling warmly.

"Sans!"

Sans sniffed the air, your nervousness subsiding.

You ran to hug him, Sans returning the hug and affectionately rubbing the top of your head.

"glad you're back, (y/n)."

"Back? Did I go somewhere?" You joked, retreating and looking up.

"yeah, and i have quite a few things to explain to you right now." He motioned the mattress. "you might wanna sit for a little, it's kind of a long explanation." Sans walked to your mattress and sat down at the edge. He invitingly patted the open space next to him.

You sat next to him and for the next few minutes, you intently listened to his long explanation of everything he knew so far. When he finished, you looked bewildered and your brows knit tightly together in deep thought.

"So I was in heat for the past four days?"

"you still are. hopefully, magic-induced human heats don't last as long as monster heats." He wasn't counting on it.

"Should I just stay in my cave the whole time?" You questioned. Sans nodded. You purse your lips together, rubbing the back of your neck. You looked uncertain and a little confused. You eyed his skull, multiple little scratches etching across his eye sockets and cheeks. “Was that me?” You frowned guiltily.

“you’re stronger than you look, you know.” Sans lightly chuckled.

“I’m sorry.” Your eyes catch his, he notes the sincerity.

“it’s not your fault, heats make everyone violent.” He knew, there were many times he almost bit his brothers head off just for knocking on his door. “they aren’t so bad, i’ve been claiming the entire first half quarter of the forest.” No one will _ever_ get near you, he’ll make sure of that.

“You own it? Did you sign some papers or something?” You rise and grab your lantern, muttering about needing more oil.

“uh, not exactly….” Sans fidgeted. You know about heats now, how is he supposed to explain that he practically called dibs on you?

“So what did you do?” You open the lantern and fiddle with the lighter. Sans cleared his throat, he’s known you for years. It’s for the best to be honest.

“i maybe, sorta, kinda, might have… claimed… to mate… you….” He didn't dare to look up.

“What?” Your voice demanded. Sans lowered his head.

“the-there wasn’t much else to do. it’s the only way other monsters will listen.” Monsters never listened to anything other than instinct. You were silent for a while before you huffed.

“Fine. It’s not like you were planning to mate me.” You chuckle dismissively.

Sans looks up again, a laugh bubbling in his chest.

“course not, what kind of a friend would do that?” Not him, nope. His skull heats, beads of sweat forming. He watched you tinker with the lantern again, an awkward silence filling the air. He guessed that stage two, though you were back from an aggressive state, still left traces of hostility. He scratched his knee bone thoughtfully, he’ll just have to get used to it.

“you know i have to stay here with you, right? just till this heat passes over?” Just for protection. He can mask your scent but he can’t ever mask your soul and the sounds it will make if left unattended. “monsters are competitive during heats, and stars knows what will happen when they found out a human has been living underground, unnoticed.”

“Is that a good idea? You told me heats can make a monster uncontrollable of their actions.” You raised a brow. There was no accusation in your eyes, just genuine concern.

“course. i’ll just sit next to you and guard, so to speak.” He’ll have to ask for some days off, wouldn’t bother Undyne or Paps much. They became more lenient with his sentry job when monsters found a way above ground and began hunting.

“Okay, just get your stuff on over. We’ll have a slumber party while we’re at it. Why not make the most of it?” You lay your lantern down. “Bring some more oil too, please. I’m almost out.”

“sure. i’ll be back in a few. imma go and tell paps where i’m staying and get a few things.” He stood up, ready to teleport.

“It’s not going to be suspicious that you’re staying in a cave for a few days? Wouldn’t that sound weird?” You question.

“nah, he’s used to me staying some nights here. thinks i’m finding a new tunnel into the Ruins. he’s been interested what’s behind the door lately.” He didn’t understand why. He’s told Paps what was there. Seeing is believing, he guessed.

“Alright then. Just bring some pillows and blankets, you can sleep next to me.” You walked over to your mattress, sitting down.

Sans wasn’t sure that was the best idea. Actually, he thought staying with you overnight was a **horrible** idea, but he'd be damned if another monster waltzed in your den, bred with you, and reported you to that lousy Queen. No, you’ll be safer this way.

Unfortunately, Sans has absolutely no self-control. So it was his guess what would happen.


	3. It Begins

**Summary for the Chapter:**

> Sans' wants morph into instinct.

**Notes for the Chapter:**

> I'm still alive! 
> 
> And I apologize, this chapter is short because I didn't want you guys to wait any longer.

When Sans arrived home, he took himself to his bedroom and began rummaging through his closet, looking for his old backpack. The backpack smelled a little musty and was lined with a thin sheet of dust. He decided to wash it along with his clothes, he didn’t want the odor seeping into your cave, it would take days to get rid of the smell.

As he waited for the items to dry, Sans took the opportunity to hunt a quick snack for himself. It was going to be a few days since he could eat again, which he wasn’t super opposed to. He’s used to going without food for weeks, he could live. You, on the other hand, geez, it was like humans constantly inhaled food and it still would never be enough. That didn’t mean he was going to reject you a meal, you still needed to eat.

After his quick hunt, he gathered his newly clean clothes and sheets and stuffed them into his backpack as a jumbled mess, his rabbit hanging limply from his jaws.

“GOOD LUCK, BROTHER! REMEMBER TO USE YOUR LEGS AND NOT YOUR BACK TO LIFT HEAVY ROCKS. AND LOTS OF ELBOW GREASE!” Called out Papyrus, just before Sans teleported away with a simple “kay, bro.”

Sans arrived at your den, his eye lights adjusting to the sudden change of lighting. He found you were simply kneeled over, tidying up your den, patting out creases of your bed, fluffing up your pillows, and setting pencils in an even row.

”you don’t have to do this every time i come over. i end up wrecking your place anyway.” Sans inquired. He set down his bag in the middle of the cave, it’s contents falling out. Sans let himself fall heavily on your bed, bouncing the pillows out of order and crumpling your blanket. You glared at him, an eyebrow raised playfully.

”I just wanted to be nice, you lazybones.” You sat up and rummaged through Sans’ bag, pulling out two thin blankets and an extra set of a shirt and hoodie. ”This is all you brought?”

”all that i had on my bed at the moment.” Sans folded his arms behind his skull and rested his head against them. ”told paps i was digging in here, trying to find a new tunnel in the ruins and such.”

”He’s not going to check up on you?” You laid Sans’ blanket on him.

”nah, said it'll dirty up his hunting gear.” Didn’t make much sense, if he didn't mind blood on it, why be bothered by dirt? He decided not to think much about it.

”Hey, Sans…?” You softly called. Sans looked over to see you laying next to him, your troubled gaze upwards and a soft dusting of red flush against your cheeks. He waited patiently, noticing your gaze would flicker back and forth in uncertainty. ”What….” You cleared your throat, speaking a little clearer. ”What was it like for you, when you went into heat?” You stared intently, waiting for his response.

Sans immediately turned red, his eye lights shrinking. What was he supposed to say? That he locked himself away in his room, furiously masturbate to ebb the desperation for a mate, and constantly silence his soul, which would humiliatingly screech for attention? He decided to leave out some of the details.

”to be honest, you really don’t have any control over what your body and soul does. especially your soul. those things can ring so loud, it’ll wake the entire underground.” He would know, remembering the many times he’d avoid many of his friends, too embarrassed to be teased by how loud his soul would be at times.

“Well, I don’t know what a soul sounds like.”

“course you don’t, you’re a human. humans can’t hear souls like monsters.”

You were silent for a few seconds before asking. ”Can you help me with my heat?”

Sans blush, which had gone away, came back with a fury. Help you? Like...like mate you? His soul thrummed, confused but excited. He… he could do that, he could help. He could be a big help.

”Talk to me during it, please.”

Oh.

“Talking helps me take my mind off things so maybe it can help me ignore my heat. Since I can’t control my body or my soul, I can still control my thoughts.” You sounded set, lighting up to the idea that you had some power over yourself.

Which couldn’t be farther from the truth. Heats suck, through and through. But if it helped you calm a little, he’d oblige. Hey, maybe it could actually work for a human. ”no problem. we can talk about whatever you want.”

You smiled, satisfied. ”Also, try not to push me off the bed this time.”

”that, i can’t help. you’ll just have to find yourself a little corner to sleep in.” He smirked and he splayed his arms out on your bed, squishing you with his heavy arm.

”I’m taking all my blankets with me. Have fun freezing.”

”have fun trying to lift me off them.”

\---

The two of you talked on and on and eventually, Sans dozed off, tired from his busy, last-minute hunt. You watched his ribcage gently rise up and down in soft snores as your eyes grew heavier and your breathing slowed.

You think it was only a few minutes into sleep where you woke up again, noticing a small tingle between your legs, weirdly and unexpectedly pleasant. You thought nothing of it and tried to resume to your slumber. As seconds passed, the tingle quickly grew into a burning fire. Your body felt so hot, finding it impossible to go back to sleep. You rubbed your thighs together, hoping to quench the flame. To no avail, you turned over to see Sans still dozing off in dreamland.

You wanted to wake him, hand reaching out but you stopped yourself. You must look really stupid, and you didn’t think talking was a good idea, especially if you were going to moan every other word. That would be embarrassing!. You decided to leave him be.

Your sight hazed, your mind going fuzzy and weak. Sans was right, you controlled nothing. Your body flushed all over, feeling as hot as you fist went into heat. But this was different. There was no pain, no anger nor fury. Instead, your body begged to be mounted on, begged for a cock stuffed inside your cunt, begged to be ravished. Your slit dripped with lubrication, dripping off in tiny droplets. It left you breathless as you tossed and turned, kicking off your blanket, it only added to the overbearing heat. Your heart pounded against your chest as a ripple of pleasure flooded your senses, blood roaring in your ears.

Dear God!

It felt like torture, a deep-seated desire for… for baring children. Underneath layers and layers of this primal demand, you knew this isn't what you wanted. This couldn't be a worse time to have kids. And with who?

…Sans?

You groaned as another wave pulsed within you. You pressed your palms and knees against the mattress, screwing your eyes shut as you muffled a weak moan. You eyed Sans, relieved he was still motionless, eye sockets shut.

Your cunt felt so… hot. Everything… just… hot.

You shut your eyes, breathing heavily.

No, you were going to be strong. You were going to get through this.

You were going to be okay.

Your heart froze as Sans mumbled, eye sockets blinking awake. ”(y/n)?”

\---

As Sans recollected himself, the first thing he noticed was your aroma. The same citrine, butterscotch smell. So sickly sweet, he couldn’t get enough of it-

Sans’ eye sockets blew wide open, eye lights dilating. A new scent had slammed into his nasal cavity, rushing all the way into his soul. He instantly recognized the very familiar seamy heat smell.

Your scent blended with your heat and coursed through his bones, forcing Sans to recollect himself before his soul prepared his body for mating.

He firmly placed his large boney palm on your mattress and heaved himself up, bringing one of his hands to rub the area between his eye sockets. He took that moment to silence his soul, who already began to vibrate violently, responding to your saccharine, alluring waves your soul released. He needed to calm down, he needed to concentrate on something else.

”Are you okay?”

Sans glanced over. You were fully wrapped in blankets, only your tiny head poking out and looking up. Your cheeks were deeply flushed, hair still rumpled, eyes half lidded.

”i can ask the same thing about you.” He muffled his soul, who buzzed in protest inside his ribcage.

”I think it’s my time of the year now.” You sighed, attempting a joke before fidgeting around your wrapped blanket. ”Seriously though, this sucks.”

”uh-huh.” His soul fought furiously against him, taking his attention elsewhere. His skull began to sweat, a grown escaping past his teeth. He’s never had to do this before. Whenever other monsters were in heat, he’d have no trouble controlling his soul. Hell, his soul wouldn’t even respond to other souls vibrations, always uninterested and uninvolved. But with yours, it was like his soul was desperate to pounce on yours, to shove itself into your soul and meld into one. He winced, creating a small magic barrier around his soul to keep it inside, finding it painful and strenuous. Once he was sure his soul was secure, he focused on you. ”it’ll be over before you know it.” A blatant lie but he heard a slight quiver in your voice when you spoke.

”Hope so. You okay?” You repeated. ”You look like you’re having some trouble yourself.”

Sans shook his head before you could finish. ”yeah, yeah, just had some stomach problems.” He slid off the bed and stood up, slipping off his hoodie over his head. ”it’s a little hot in here, imma go ahead and get us something to eat.”

”Wait!” You quickly stood up, your heat musk growing stronger, your soul sending powerful ripples to his soul, colliding against his barrier, creating a small crack. Sans scooted away, his eye lights refusing to meet yours. ”I’m not going to be here when you come back, uh, probably.”

Sans turned to you, his blush deepening. “where are you going?” He didn’t bother to let you answer. “i can’t protect you when you’re out and about by yourself. you’re staying in the cave.”

“I know it’s dangerous, but I was just going to get my bucket and get some water from the ravine. I really need a bath, I’ve been soaking in my sweat for days.”

He eyed the entrance to the cave, a very dim light shining across. “okay, but you come back immediately. no stopping for anything.” There could be monsters out there wandering around. And he was sure as hell your heat scent would attract anyone.

“I’ll be quick.” You hurried to grab your bucket.

He awkwardly coughed, blocking your view of his crotch. Sans teleported away. Your smell was killing him.

Sans stumbled in his room, sweat trailing down his skull as he broke away the thin barrier he created, releasing his soul's massive waves of galvanized exhilaration, which had been building up inside the barrier, for your soul. His soul pushed magic down his pelvis, forming a large bulge underneath his shorts. He stifled a moan, an unwanted rush of pleasure coursing through his magic. He directed his eye lights down to his ribcage, bringing out his soul. He wheezed, trying to get the smell of your heat out of his system.

He needed some relief.


	4. Running Wild

**Summary for the Chapter:**

> You fetch some water in contemplation, meanwhile Sans deals with his "problem".

**Notes for the Chapter:**

> This chapter may be little boring but hey, at least there’s smut near the end. Kind of.

You stepped back, a bit ruffled by Sans' sudden disappearance. He didn't even say goodbye. You hoped he wouldn't be out for long. You guessed it must be so awkward having your best friend go into a frenzied horny state. Of course he wouldn't want to be around you. The thought disturbed you. Him being around was very comforting, ridiculously uncomfortable considering the heat, but still comforting to have a trusted friend by your side. But as you viewed his backpack still on the floor, a mess of blankets and clothes spilling out, you knew he'd come back. At least for his jacket, he would never leave it behind. 

  
  


Well, until now but still. Speaking of which, you eyed the jacket thoughtfully. It's always cold outside. You don't have your own thick jacket on hand, you just always used your blanket to wrap around yourself before leaving your den. Using your blanket as a shield against the cold wasn't the best of ideas. Sometimes it dragged on the snow, which stuck to the fluff and dampened the material. Or sometimes you slipped on ice and fell into the snow, which would soak the blanket and would have to dry out in the cold.

  
  


Your attention went back to the jacket. You were certain Sans wouldn't mind you using it for a little while. Being set, you pulled the jacket, a little surprised at how heavy it felt, and slid the jacket on. You noticed how the jacket almost scraped the floor and when you slipped your arms into the sleeve holes, the sleeves fell limp. You looked like a child in their larger parent’s jacket. You giggled a little, bringing the hoodie close. It smelled of Ketchup and raw meat. It smelled like the earth and a slight smokiness. But mostly, it smelled like Sans. And a cheaply used detergent that didn't mask the other scents very good.

  
  


Your body began to feel warm as the jacket absorbed your body heat. You reached down to grab the bucket, fingers wrapping around the rusted handle. It creaked when you picked it up, it's tired metal worn out from months of use. You walked past the entrance, the outside chill frosting your cheeks and nose. The warmth of the cave dispersed as the wind blew harshly, shaking the trees and blowing snow sideways. Your body began to shiver as the cold crept into Sans' loosely put together jacket. You resisted chattering your teeth and continued your journey to find the river bank. Your hair blew all kinds of directions, tangling itself badly. You whined, your supposed "heat" had subsided for a mere moment. 

  
  


But now that you were outside, it decided to come back with a vengeance. You groaned, feeling the in-betweens of your legs growing wet. The inside of Sans' jacket began to heat up into an unbearable temperature. Irritation skyrocketed, as it bubbled in your gut. Of all the things to happen to you, being in heat had to be one of them? Of course, it would be. Just like being trapped in the underground, fearing for your life every day of being eaten by a ravenous beast that could tear you to shreds. You frowned, eyebrows knitting tightly together. You could get past this. If you could survive being almost eaten by Sans then you could survive a measly heat. Oh, you certainly remember the time when Sans thought of you as dinner. You recalled the time as you continued walking robotically to the river. 

  
  


Back in your first few days in the underground, it didn't take long for Sans to discover you wandering around the outskirts of the old entrance to the ruins. Especially so close to his sentry station. You remember seeing him for the first time. How he towered over you like a boulder with his massive, thick frame. His vibrating, intense red eye lights staring down at you with the inclination to maim. His dull fangs clenched together in a fury, as his large skeletal hands curled over your much smaller frame. You weren't considered short in human standards but compared to Sans, you were a dwarf next to a gargantuan. Well, not really, that was an exaggeration but he was still much bigger than you. Big enough to… pounce on top of you… straddle you...! You stopped yourself, feeling sick to your stomach, irritation tenfold. How dare you think about your friend in such a way? You can already imagine the disgusted look on Sans’ face, how he wouldn’t ever want to hang around you anymore. No, your relationship was purely platonic and nothing more. Besides, Sans would never think of you in such a way. Never in a million years. 

  
  


A distant rush of water pulled you from your thoughts, as you arrived to find the river. Chunks of ice floated on the top, bobbing up and down as the water steadily carried it gently downstream. You crouched down, bringing your bucket forward. You rolled back the large sleeves as Sans’ jacket fell over your knees. You placed the bucket on the surface of the water and put your hand inside, pushing it down to break the surface. As soon as the freezing water came splashing in, you quickly pulled your hand away. You decided to rub your wet hand on your cheeks and forehead, to calm your red flushed face. The windy air helped to calm your heat, but it also could make you deathly ill. You couldn’t stay out here for long. 

  
  


The bucket didn’t take long to fill, you heaved both yourself and the bucket up. The water-filled tin groaned underneath the weight, it rocked back and forth in your hand. It felt very heavy but you fared well. On the way back to your den, you dipped your hands in the bucket a couple of times and brought it up to drink. The cold water hit your gut like a punch, but it relieved your dry, sticky mouth. You wondered when Sans would come back. You hauled the bucket inside your den, walking slowly and dragging your free hand across the cave wall. It was a way to find the correct tunnel and not get lost taking the other more narrow, tight spaced tunnels. Once you arrived, you brought your battery charged portable heater, which Sans brought as a gift a couple years back, you placed the bucket on top and set the temperature to the highest degree. All you had to do was wait. And wait. And wait….

  
  


You laid back on your bed, your back against your pillow, leaning against the wall. You sang an old tune, made popping sounds with your mouth, and desperately ignored the burning heat, a slick clear wetness trickling down your thighs. You groaned. You felt very hot as if you were sick but you weren’t sick, you were just fine. Christ, you’ve never felt so horny. You lean back, shifting your legs. No, no, you need to keep yourself together. 

  
  


You need to learn how to control these… urges. 

  
  


You need… a better bed. 

  
  


The pillows were piled up on one side and blankets flattened. They should be moved. You flipped over your sheets and crumpled them together, forming a circle with you in the middle. 

  
  


It needs more. 

  
  


You down to San’s pack, his sheets falling out. You grab everything even his own hoodie. You patted everything into the rim of the circle. You took a moment to observe to what you now suspected was a makeshift nest of pillows and sheets. You sighed, letting yourself fall inside and nuzzled into the rim. You stayed in an almost fetal position inside the nest before you blinked a few times, realization seeping in.

  
  


Did you really just make a nest? 

  
  


How fitting, you think sourly. You half a mind to dismantle the nest and put everything back in place but you oddly found comfort in it. You decide to keep it, at least until you’re done with your heat. You flip yourself over, finding a comfortable position. The nest shouldn’t matter, it’s Sans you worry about. He’s been burdened by you for the next few days, he’s bound to get tired of you. Guilt sank low into your belly as you shifted closer to the bottom of the nest. 

  
  


Your eyelids feel heavy and your breathing slowed. You found it odd to be so tired after having slept for hours. Then it occurs to you that you probably only slept for a couple hours, time wasn’t something you kept track of down here. You allow your eyes to close slowly, the warmth inside the den sweeping over you like a blanket. Sleep pulled you away from the world.

  
  
  


___

  
  
  
  


Sans sat on the edge of his bed for the past few seconds. He had to cool down, he had to take the time to calm his soul. He really didn't want to end up doing something awkward or violating to you. Heats… change a monster. The primal need to mate and breed overrides common decency and easily crushes even the most strong willed monster like a grape. He ran a skeletal hand across his face, breathing deeply. He felt relaxed and back to normal. 

  
  


Till his soul recounted the smell.

  
  


It clogged in his nasal, choking the daylights out of him. He felt his soul push magic across his bones, wrapping around his already sensitive ribs and pelvis. He watched in disdain as a bright red bulge took form underneath his shorts. He suppressed a moan, wincing at the sudden intrusion of magic. Sans brought his phalanges down to rub against his crotch. The amount of magic pushed down his shorts overwhelmed him, making him realize just how much he suppressed back in the cave. 

  
  


His cheekbones grew to a vibrant red and his jaws parted to pant ever so slightly. Drool escaped past his dull fangs, his long flat tongue slipped out and hung loosely. He grinded against his own hand. His mind clouded as his thoughts came to you.

  
  


_ You'd be lying belly down, ass up in the air, waving invitingly to him. Your face flushed and enamoured with lust and excitement. Your mewls would echo across the cave walls, calling for her mate. For him. _

  
  


Sans lifted his shirt ever so slightly, giving way for his free hand to roam. He could see his red magic softly glowing and engulfing his bones. He ran his hands gently across his rough, chalky textured ribs and almost choked.

  
  


_ "Sans!" You'd cry desperately, staring at him with half-lidded eyes. Your under garments would undoubtedly become soaked, leaving a noticeable dampness. You'd curl your fingers into your bed sheets, desperate for any contact. _

  
  


Sans pulled down the hem of his shorts, his cock bouncing up freely. His hand hesitated in the air. Shame filled his soul. But it left as quickly as it came, his magic responding to the heat smell locked away any other emotion besides crushing lust. He took a moment to lap at his hand, leaving a thick trail of drool for lubrication. His sharp pointed phalanges wrapped hurriedly around his cock. Sans squeezed his eyes shut as relief flooded into him, letting a heavy moan slip past his teeth.

  
  


_ Sans wouldn’t let you endure the pain for any longer. He’d crouch low, his soul releasing pheromones and scents. He wanted to affect you as much as you affected him. The scent of him would overwhelm you no doubt, only doubling your desperation. You’d respond with a simple courtship. Rising up only for a moment to rub against his clothes, nuzzling underneath his neck, to become covered in his scent. _

  
  


Sans choked out a low whine. He stroked faster, gently squeezing tighter. He leaned back slowly to fall against his bed, soon trailing his sharp fingers across his lower ribs. He hissed, the added pleasure almost unbearable. “hah….”

  
  


_ Sans would bend down to drag a tongue across your neck up to your cheek, enjoying your small giggles. He’d push you down gently by your chest on the old mattress. His hand would trail down to your chest, bringing a sharp pointed index at the hem of your sweater and slowly rip away at the material. _

  
  


“Nnf…” He kept a steady pace with his hand. His feelings for you, your heat scent, and his own self pleasure melted together. That’s right… his feelings. Sans never gave it much thought before. All this time, he was only thinking of helping you in your heat. He was just now realizing that… he might be in love with you. Sans slowed but never ceased his hand bobbing up and down. 

  
  


He opened a single eye socket. The skeleton could take it as the heat messing with his mind again but that was never the case. These feelings long developed before then. Everything about you, he enjoyed. Your laughter, smile, endless support, genuine care for him, it all added up into something marvelous. Yes, the more thought he gave the idea, the more he believed it was true. 

  
  


Only now, your heat, was a sensitive time for any monster or, in your case, human. You’d still need help and the idea of helping you himself never went away. 

  
  


For now though, eyeing the glowing appendage between his legs, he needed to finish what he started. He rolled himself upward, knee bones dig into the couch and one hand steadying himself. His phalanges trailed under his shirt, through his sensitive ribs, and reaching out gingerly towards his soul. 

  
  


His soul glowed vibrantly, pulsating like a human heart. It shimmered excitedly as his index gently trailed up. Sans had to clench his jaw tightly, eyes scrunching up. “gah!” He whimpered. Heat spread throughout his body, sending a flurry of need. 

  
  


He didn’t need imagination anymore, feeling as if he were going to explode. He was taken aback for a few seconds, wondering how pent up he must’ve been to approach his end so quickly. But then again, soul sex, or rather masterbation, was a quick and easy way for a monster to relieve themselves. And that’s just what he was going to do.

  
  


He began slowly pushing his digit in his moist soul, eliciting a moan. “Hah, (y)-(y/n)!” He needed you. He needed you pinned under him, back to the floor, legs wrapped around his hips. He needed to be inside you, desperately knotting, breeding together.

  
  


A knot.

  
  


That’s what would satisfy you in the long run. A knot stuffed inside your puffy slit, spurting his seed, holding you down as you would no doubt be rutting back, lost to a dazed heat. And he would give it to you. He would give it to you gently and so tenderly.

  
  


His hand began squeezing lightly at his cock again, jerking rhythmically. Pre-cum came out in tiny spurts and he felt his knot inflate. His single digit in his soul rutted at a slow pace, only spurring Sans on. He was a goner, his orgasm erupting. He checked out a weak and muted cry. Thick strings of crimson flew out in large globs as Sans gripped at his swollen knot, his soul dripping small amounts of magic in his chest.

  
  


His cum stained his bed sheets and his shorts, a very noticeable glow to it. He breathed out heavily, taking a moment of pause. 

  
  


Sans stayed in that pose for a good while before pulling out his phalange from his gelatinous soul, muffling a moan. He wiped his hands on his sheets and pushed himself up, pulling up his shorts. He sighed.

  
  


He’s such an idiot. Creating any form of monster cubs would require a soul bond. But not humans. He’s heard the stories before.

  
  


Humans don’t need a soul bond to create cubs.

**Notes for the Chapter:**

> I have a tumblr if any of you are interested. Feel free to ask me whatever you’d like.
> 
> https://www.tumblr.com/blog/candlewaxwrites


	5. Be Alert

**Summary for the Chapter:**

> Emotional and territorial obstacles stand in the way.

**Notes for the Chapter:**

> A bit of backstory to this mess of a fic. You know, this might not actually be a short story, cause I planned ahead and ya'll are gonna be receiving way more than a handful of chapters. Might change the tags a bit too so we'll see.

_ i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid i’m so stupid- _

  
  


Sans stuck the mantra in his head, hoping that even a modicum of sanity could return to him. He crawled on all fours, dipping his head low to hide from the rather large prey in front of him, a lean buck. The wind blew past him and towards the prey. Sans prayed that his scent wouldn’t carry towards the buck and accidentally scare it off. He currently hid behind thick trunks and round bushes. 

  
  


He can’t believe he jerked himself off just by thinking of you. You! To you! Of all beings on earth, it just had to be a human. Sure, he gave little thought to how he would settle down with a mate and produce the next generation but he’d never thought it would be to practical livestock.

  
  


...he also can’t believe how he just called you livestock. Sans mentally scolded himself. He can’t help you with your heat, what is he thinking? Any form of mating ritual with a human would result in an instant pregnancy. 

  
  


Sans had gone hunting to take his mind off things, which brought him to now.

  
  


He was above the underground, a forest rich with plant and animal life. The forest provided a well-stocked hunting ground for Sans, thankfully ignored by other monsters. After all, monsters preferred the delectable, sweet taste of human flesh. 

  
  


Years ago, a scrawny young human fell underground. They befriended and won over almost every monster with their charm and kind words. But the King Of All Monsters took advantage of their compassion. Once the human freed everyone, the King swiftly dug his maw into the human, killing them as he ripped away flesh and bone. He had done this as an example to all humans and monsters. For humans, it was a warning, they could flee and hide all they want, but they remained food.

  
  


For monsters, it was an invitation. Monsters had been trapped for decades, the only way to satiate their hunger was consuming humans. Neighborhoods, shops, and schools became popular targets and hunting grounds. Humans declared war and genocide but nothing seemed to put an end to the feeding. All popular human cities and towns were nothing but a barren wasteland, an empty memory of a world so previously overpopulated and dominated by these Homo-sapiens.

  
  


Sans was surprised at how quickly they came to their downfall, fated to a painful demise. Monsters _ did _ love to eat humans while they were still alive, screaming and begging in their last moments as their limbs and faces were torn from their bodies.

  
  


Guilt pulled heavily at Sans. He can’t even recall the number of humans he’s eaten, let alone killed for mere game. Not that he regretted snapping their rib cages in half, he just imagined how frightful and monstrous he must’ve seemed to you.

  
  


You came into the underground for refuge, a place once occupied by these man-eating beasts. You expected a ghost town but instead faced one of the most dangerous, maniac monster to have existed. 

  
  


Sans furrowed his brow, breath stilling. The buck leaned over and munched sweet grass into its narrow maw, ears flickering tentatively. It’s muscled hooves stepping delicately away from mud as it breathed heavily through its nostrils.

  
  


Sans carefully put a clawed hand forward than the other. He crawled gingerly, hoping that the buck could move _ just _ a few inches away so he could enter its blind spot. The buck seemed to have no intentions to move. Sans would have to move carefully. After a few moments, Sans readied his back legs, swaying his hips, preparing to pounce. In a flash, Sans has leaped over the bushes, pushing over the terrified, shrieking deer on its side, Sans locker his jaw on the bucks neck, biting down. There was a crunching sound, the deer halted it’s screaming, his head flopping over dead. Sans pulled away. 

  
  


Hunting was as easy as breathing to him. He’d have to skin, cut it up, and serve it to you but it’ll all be worth it. 

  
  


Sans gripped the deer in his arms and teleported home. 

  
  


For a few hours, he prepared your meal. Once he realized how long he took, he hurried his process and scooped the cooked meat in a plastic storage container, shortcutting to his sentry post. The most he could do was provide some taste, giving you a choice of ketchup, relish, or mustard. He flung a few packets into the plastic container. That’s when an unfamiliar scent crashed into his nostrils, sending Sans into high alert. 

  
  


There is an intruder. 

  
  


Sans turned his skull, eye lights shrinking. Icy fear clawed at his spine, meddling with the rising fury of whoever dared challenge him for his claimed territory and especially the female in heat. He clamped his jaws shut, reminding himself not to maul the competitor alive. All he needed to do was chase them away. He knew he should’ve stayed vigil, he was an idiot to leave. Trekking lowly, Sans left your food on top of his stand, attempting to locate the intruder. 

  
  


He lifted his stocky visage in the air, recognizing a few of the scents. The stench fumed past the pine trees. He discerned it to be male, another smokey scent intermingling with it, and… wet dog? Sans rounded a pine to find the competitor, bent over with a paw on his hips, a black nose wiggling against the edge of the icy bank. Sans couldn’t help the low, irate growl escaping past his fangs. Doggo’s black ears perked up as his head turned towards Sans, squinting his pale eyes. 

  
  


“Sans.” The old, blind mutt muttered. “You’re past your station.” His ears lay flat on his head.

  
  


“and you’re far from yours. why are you here?” Sans’ question curt and almost interrogating. 

  
  


“You’re one of the best hunters of monster kind, your scent tracking is one to admire. You should know what that smell is….” Doggo swiped his tongue across his thin black lips, eyes rounding. His scruffy tail began swaying in excitement.

  
  


Sans’ fear had come true, a monster discovered the human in heat. _ His _ human in heat. He was thankful that the mutt could not see, as Sans’ form deflated and his maw formed into a scowl. He wanted nothing more than to snap his jaws around the stupid dog’s neck. Sans was going to warn the dog before the mutt spoke again.

  
  


“You also should know that I’m no fool. I scented your territory markings,” Doggo’s pale, moony eyes shifted back and forth. “And there just so happens to be a female in full bloom. She smells wonderful.”

Sans gritted his teeth, instinct rattling his soul. This was the competition he expected. Without thinking, Sans’ soul shot out challenging vibrations. The mutt was surprised for a moment before taking a stance, fur bristling.

  
  


“Who is it, Sans? There are only so many monsters down here.” Doggo’s soul shot back angered vibes, accepting his challenge. 

  
  


“you haven’t answered my question, why are you here in the underground?” Sans prepared his footing.

  
  


“Can’t an old friend say hi?” Doggo didn’t look particularly friendly, his stance devious.

  
  


A snapping of branches caught both of the monsters' attention. It came from behind Doggo, who turned his head. His fur lay flat and his ears perked, tail beginning to wag. Sans took the opportunity to pounce on the intruder’s chest, knocking the air out of him. Doggo struggled under Sans’ iron hold before giving up, the fear scent wafting into his nasal.

  
  


“What are you hiding, Big Red?” Doggo was frightened but he didn’t let it show, pulling back black lips to reveal a row of yellow-tinted fangs. His muzzle scrunched as he pushed out a snarl, attempting to scare Sans.

  
  


“if you know what’s good for you, you’ll stay out of my territory.” Sans grasped his skinny neck, squeezing around it till Doggo gagged. If Doggo could see, the image of Sans would surely terrify the old dog. Red magic poured uncontrollably from his eye sockets and rib cage. His once large eye lights shrunk down half its size but the luminescence doubled, large black eye sockets wide for bloody murder. The mutt breathed raggedly, he began digging his claws into Sans’ hand and kicking into his wide chest, hoping to somehow knock him off. But it was like moving a boulder. Sans gave the mutt mercy and got off him. Doggo shot up, hacking in air and grasping his neck, eyes wincing. 

  
  


Doggo glared at him with those pale eyes before rising slowly. 

  
  


“How do you think the others will find out about her, huh? The captain will demand to know and you better thank your lucky stars the queen hasn’t found out. And what about your brother?”

Sans hesitated before asking. “d-do you know-”

  
  


“I know she’s a human, Sans.”

  
  


Fear gripped his soul as the hope of keeping you a secret shattered, his strong domineer deflated. He tried to shrug it off as a joke as if the old dog was losing his sense of smell.

  
  


“Don’t sway it. How long did you think you would keep her a secret, huh?”

  
  


“get out before i choke you to dust,” Sans bared his massive dull teeth. He didn’t want to hear any more of it, he could already feel his soul quaking. “if you tell anyone about her… i’ll kill you.”

  
  


“Watch yourself, Sans.” And in a blink, Doggo was gone. 

  
  


Sans leaned over, hyperventilating. His eyesight became slightly fuzzy and the wind of the snowy underground was muted. He can’t let them find you. He can’t let them take you away. He squeezed his eyes shut

  
  


No.

  
  
  
  


No.

  
  
  
  
  


**No**.

  
  
  


He teleported away.

  
  


Sans trudged inside the musty den, the recognizable must scent clogged into his skull already. He almost wanted to teleport away again, he wanted to pretend he didn’t just jack off to the image of breeding his best friend. But the sweet clarion call lured him deeper. The scent shoved away the wet dog smell and even the deer smell (which Sans scolded himself for forgetting, but he didn’t feel like going back.)

  
  


Sans noticed that he was walking a little faster, his sour, dreadful mood (caused by the worry of other monsters eventually finding out you exist) vanishing, suddenly replaced by a kindled fever. A tingle began in his spine, pleasant and alluring. The closer he was to you, the stronger the tingle became, morphing into titillation**. **His good mood skyrocketed, his scowl lifting upwards into a hopeful grin.

  
  


The first thing that caught his attention, when he entered the cave was you cocooned inside a blanket, your head popped out, eyes closed in a peaceful slumber.

  
  


The second thing was the over boiling pot of water. Bubbles fizzed around rapidly at the top, spilling over and creating a hissing sound when coming into contact with the fire below. Sans turned off the portable stove.

  
  


He looked over to you indecisively. 

  
  


The smell. 

  
  


The familiar citrine, butterscotch scent blended so perfectly with the heat curled around the air, inviting him to come closer.

  
  


And he obliged. The next thing he knew, Sans was hunched over, claws fiddling with the edge of your nesting area. He titled his head, realizing you must have created a makeshift nest while he was out. He chuckled. It was a natural thing to do, sure, but seeing a human make a nest made for a good laugh.

  
  


But as he let out his breathy chuckle, the heat smell forced itself into his nasal with full force. His cheekbones light up as his soul twirled in excitement. 

  
  


Shit.

  
  


Probably shouldn’t get so close to you. Even asleep, your soul released the ancient mating call.

  
  


Still, he had no intention of leaving you alone again. He never wanted to leave your side but… the _ smell _.

  
  


If he could just… just… see what it smells like… up close.

  
  


Sans leaned over, pausing just at your face. He was just centimeters away from your resting face. Your breathing was so slow and rhythmic, your hair a mess, and your lips parted slightly. He gulped, hesitating a little before gently pulling away the blanket to reveal your neck. 

  
  


Here is one of the two places the heat scent wafted so deliciously from. Your neck lies bare before him and Sans wanted nothing more than to lick and taste you. He gave one last glance at you before digging his nose at the cradle.

  
  


He shuddered. Oh, sweet manna. His ribs tingled delightfully. He needed more. His giant maw separated to lap languidly at the thin sheen of sweat and slight dirt. 

  
  


He never tasted anything better. He gave a few more laps before he heard a few giggles and felt you shifting away, facing the ceiling of the cave. 

  
  


His soul stopped before he realized you were still asleep. You must’ve felt ticklish but it wasn’t enough to wake you. He pulled away before stopping and looking at your bare legs and nothing but underwear covering your crotch.

  
  


Sans looked away, a little guilty to have looked for long. Your open legs gave way for the second and most desirable area the heat scent collected.

  
  


He… he really shouldn’t look. 

  
  


Sans’ imagination ran wild, and his instincts to get close and rub up against you was strong. Stronger than his morals. He doesn’t know how long he can avoid you before giving in. And it seems he only has seconds to teleport away.

  
  


He was just about to when you stretched your legs and groaned, followed by a yawn and a tired sigh. Your legs were spread rather widely open. And if the smell wasn’t strong before, it was like an explosion now. There was noticeable circular dampness on the front of your underwear.

  
  


It was about a few seconds of staring when Sans lost control.

  
  


He went for your legs, positioning his head just above your crotch. A part of him screamed to stop, begged to go home and not ruin this relationship. But the larger, more dominant part wanted something more sinful.

  
  


To tear away the thin fabric and shove his flat, thick young’s inside-

  
  


“Sans?”

  
  


Sans doesn’t remember jumping up to high in his life. Well, he didn’t technically jump, but he lifted his head and upper body up so quickly. He felt his soul leaving his body.

  
  


“What are you doing?” You drowsily asked, rubbing your palms against your eyes, blinking out any blur.

  
  


Sans started to sweat. His tongue was sticking out, mouth agape. He gripped tightly onto the edge of your blanket. 

  
  


Did you see him…?

“i… didn’t know you were awake.” Sans pulled his tongue back in, wiping his arm across his teeth, picking up the drool.

  
  


“I wasn’t.” You got up, scratching your neck. Your scent overpowered him. Sans leaned back a little. He pulled the blanket to cover your lap.

  
  


“you looked cold.”

  
  


“How long was I asleep?” You look around with half-lidded eyes, blinking thoughtfully. 

  
  


Oh, stars! The scent! Magic poured into his pelvis bone, as his soul buzzed wildly. “long enough for the water to boil over.” He half-heartedly jokes. 

  
  


“Shoot.” You glanced over to find the mini stove turned off. “I was gonna take a bath but, eh. I’ll do it tomorrow or something.”

  
  


“still tired?” The heat had a vice grip around him. Sans willed himself not to topple you.

  
  


“Not really….” You stared at him with narrowed eyes, a small frown across your lips. 

  
  


Sans felt anxious. You stared at him for a good couple of seconds before sitting yourself up on your knees. You stretched your arms out, bending backward until a few popping sounds erupted.

  
  


Sans gawked, baffled. Were you doing this on purpose? You have to be.

  
  


“When’s the last time we cuddled?” 

  
  


The question was so out of left field. Or maybe very appropriate for this situation. Sans didn’t know. But what he did know is his bafflement. Cuddle? Sure, you guys cuddled lots of times. But his memory serves him wrong, a bit fuzzed on when the last time he was pressed up against you, nuzzling his open nose hole into your cheek, stealing a few lipless kisses from your forehead.

  
  


….

  
  


….

  
  


….

  
  


Sans isn’t sure if his shared friendship was ever entirely platonic.

  
  


He felt a pressure on his chest, then a soft sigh. Sans looked down to find you pressing your cheek against him, almost like an affectionate kitten. And he swore he could hear a barely audible purr. 

  
  


The display was adorable and out of character, surely a result of your heat affected mind. Sans, himself, became wracked with a surge of arousal. He growled lowly, eliciting a tiny squeak from below him. The adoration and tingle of fear in your eyes made a pause. Sans blinked, attempting and failing to force down the lengthy spasms of need. 

  
  


You were so close to rubbing against his glowing stiff. His bones burned painfully, he wasn’t thinking clearly when he wrapped his arms around you. “you smell good.” He stupidly blurted. He took a deep breath, eyes fluttering happily. 

  
  


“Really? Cause I think I’m musty.”

  
  


“You don’t smell bad at all. you smell like oranges. and rice pudding.”

  
  


“Like a dessert?” You breathily laughed, taking your arms and attempting to try to hug him. 

  
  


It looked awkward. You on your knees, scooching closer and him in a criss-cross, with your kneecaps digging into his legs. You looked like a child compared to him. 

\---

  
  


You never prided yourself on your sense of smell. Often, your nose would clamp shut if your body felt even an inkling of illness, forcing you to sleep with your mouth open, tongue and gums dry and lips crusted unnaturally.

  
  


But the air. The odor. Sans. The smell wafted closely, a strong scent. You yearned to find that tantalizing aroma and track it down. It kept stirring around, taunting you. It held a prize at the other end of it practically danced around you.

  
  


It was almost like he was wearing cologne, but you know for a fact that Sans never bothered with that kind of stuff, deeming it too frou-frou for his taste. 

  
  


You couldn’t, for your life, figure out why your brain registered it as good, but you didn’t complain. This… heat, as Sans called it, you realized it forced you to act on some sort of monster instinct and that you understood what it wanted and needed.

  
  


That’s probably why, when Sans stood over your previously dozing form, you felt a surge of primal achievement. Part of you strongly pleased that you could attract such a strong and powerful mate. Pushing down the physical feeling of need proved worthless, you came to terms with the fact that you had to carry this heat out and all its horrible factors. 

  
  


It’s factors including pressing yourself up against Sans and rubbing your cheeks and nose all over his chest. His scent was comforting and familiar. All you wanted was to rub his scent on every inch of your body. You thought that acting out on this instinctual want would hopefully satiate the heat. Only it didn’t. Your body temperature heightened, cheeks flushing and neck beading with sweat. 

  
  


The sad truth was that you were completely lost in your heat. You had been the moment Sans decided to waltz himself right into your cave. You couldn’t bring yourself to blame him. He meant well and only wanted to help. At this point, he was doing more damage than good. 

  
  


You looked up, watching his dazed expression blinking lightly. He must be as lost in this as you were. You pretended to not notice the obvious bulge between his legs and scooted closer. 

A small part of you screamed to stop this, demanding that you pull away and end this rather amorous, affectionate display before you do something you’ll regret. The larger part dismissed the protest, dampening between your legs and shoving your heat scent into Sans so he could smell nothing but.

  
  


You just had to be under some sort of spell. Otherwise…. It was you doing this. You ignored it, preparing yourself to settle into his lap.

  
  


Before you could, something felt wrong. It stopped you from continuing and you turned to the entrance of the cave. You went still and quiet.

  
  


Sans seemed to notice it too, the adoration in his eye lights dimming out and bringing a fire of annoyance and rage. 

  
  


A deep panic settled into your chest. You breathed rapidly, mind and ears on high alert. Somehow you knew there was an intruder. Foreign and undetectable but an intruder ready to overtake the den.

  
  


It disappeared as quickly as it appeared. You were left in utter confusion but the terror didn’t dissipate. It grew rapidly, to the point where you began hyperventilating. Your chest felt tight and heart thrummed. 

  
  


The only thought you had was to run.

**Notes for the Chapter:**

> Oof, cockblocked by a smell. Don't worry though, the smut will come sooner than you think.
> 
> https://www.tumblr.com/blog/candlewaxwrites


	6. Shovel Down

**Summary for the Chapter:**

> Sans digs himself into a hole.

**Notes for the Chapter:**

> Sooo, I definitely have to change the warnings for this fic.
> 
> Warning: Kind of non-con in this chapter.

You anxiously twirled your head around, your frightful bulging eyes settling on the large black gaping entrance. It seemed to tower dauntingly, echoing the rumble of harsh winds outside. Though it posed threat of lurking intruders waiting to protrude and attack any second, it also harbored secure, tight tunnels that could swallow them whole.

  
  


You would be safe there too. You could huddle within crawl spaces that no monster could ever hope to squeeze inside. Your heart lurched, imagining an egregious monster fumbling his big heavy paws on top your back forcing you to-

  
  


You jumped up to your knees in panic only to feel strong, heavy arms clamp around your middle and pull you back down. You didn’t fight it but you groaned in irritation. Your chest felt tight and your breathing fell short and rapid. Soon, a large warm hand rested itself on your head and began stroking gently. The action was unexpected but you didn’t push it away.

  
  


You began to calm down, falling limp in its hold.

  
  


“you’re okay. you’re fine.” The deep voice spoke so softly, the baritone is rich like melted chocolate. 

  
  


He smelled so nice, like cologne but not as strong. You leaned into his touch.

  
  


Sans.

  
  


You’d be dead, nothing but chewed up flesh and bone digesting inside wicked monsters if it weren’t for Sans. He fed you, gave you gifts, kept you safe. A surge of admiration blossomed in your chest as you looked up to him. 

He gave every reason to terrify you, a large stocky stature big enough to kill a buffalo, teeth as wide and dull as an overgrown bulldog, and an animalistic personality that would eagerly maul any living being at close proximity. But he managed to become as gentle as a mother's kiss and as sweet as one too.

  
  


It didn’t register soon enough when your small, plump lips gingerly touched his sharp-toothed maw. Sans grew deathly still, eye sockets blown wide and red eye lights shrunken and pulsing.

  
  


You pulled away hurriedly, stuttering and ashamed. “I-I-“ You really blew it this time. You swallowed thickly, throat tight. “I’m sorry.” You averted your gaze, instead looking down in sheer embarrassment. “It’s a heat thing, isn’t it? I’m not thinking straight today. I know you don’t like me in that way.” You tried to untangle your arms and torso from his grip but he held tight. You raised a confused eyebrow at him.

  
  


“...what if i did?” Sans had released you from his stronghold, you moved only slightly away. Sans began nervously fiddling with his phalanges. He drew in a deep breath, fumbling for a strip of courage. Maintaining your speculating, hard gaze took great effort. Sans genuinely looked earnest but any words he had fizzled away.

  
  


You gulped. “Do you?”

  
  


“um, yes? i don’t know.” He grimaced, cheekbones completely flushed. “i think i have been like-liking you for a while.”

  
  


You stared at him, deep in thought. Well, this is a surprise. First, you kiss him because of your heat affected mind, then you thought he’d brush it off as quickly as you did… as you wanted him to. But he didn’t, he just confessed his feelings. What were you supposed to say? 

  
  


...Did you feel the same way? He was kind, kinder than he was the first time he met you, considering he tried to eat you. He changed, thankfully. He became a very close friend. Never in a million years would you think you would have such a close bond, especially with some hulking, human-eating monster. And never, would you think, the monster would fall in love with you. 

  
  


Evidently he did. Sans protected you, made sure you wouldn’t starve and kept you company. He was pretty funny too, albeit his puns were a bit overbearing, you didn’t mind too much. The more thought about it, yes. You did return his feelings. 

  
  


“I think I like-like you too.” You confirmed, giving a small shy smile. 

  
  


Sans’ grinned widely, his eye-lights shining brightly. “thank the stars, would’ve been real awkward if you didn’t.” He leaned over and hugged you, a purr rumbling in his chest.

  
  


“You chose quite a time for a confession.” You attempted to laugh but it melted away. You squeezed your thighs together, hissing. “But… I’m glad you told me.” You flushed beet red, placing your hands on his chest and pushing yourself away from him. “You could have told me after my, um, heat. You know, when I’m not in the state to rub my coochie all over you.”

  
  


“i can help you!” He blurted, his voice cracking up an octave too high. He cleared his throat, his pants suddenly tight again. “i--i can help you.”

  
  


You narrowed your eyes at him, perplexed and suspicious. “How, exactly?”

  
  


“if-if you’re up for it, not that you have to, but if you want… maybe we can… do the do?”

  
  


“Like have sex?” You gawked.

  
  


Sans jumped up in surprise before bellowing with laughter. “Yeah. I was trying to be discreet, you know.”

  
  


“I don’t think I’m in the mood of raising little half breeds.” You frowned, pushing yourself away despite the ache emitting from between your legs that part of you would gladly like to shove it on Sans’ nasal hole.

  
  


“monster breeding requires a soul bond. as long as our souls don’t rub up against each other, we won’t have a problem.” He forced a rather wide smile. Something about it made you uneasy but you dismissed the feeling.

  
  


“I’m a little hungry.” You complained, shifting the conversation, curling back into your makeshift nest. 

  
  


Without a word, he popped away from the cave.

  
  
  


\---

Sans teetered back and forth, a bit dizzy from his haste to retrieve the plastic container he left on his station. His soul felt light and fluttery, a warm pleasant feeling blossoming.

  
  


He couldn’t deny it any further. He is deeply in love. What makes that better is that you return his feelings! He felt giddy as a schoolgirl. The first thing he needs to do is the courtship. He’s already got the food in check. All he really needs is to bring out his soul, make sure it doesn’t touch yours and hope you’re infertile. 

  
  


Actually, that would be disappointing. He hopes and practically knows that you are a prime dame, ready to be bred with pups. Or pup in your case. 

  
  


Then he remembered the intruder from before. Not the old mutt, but the mysterious one lurking just outside your den. His soul flamed wildly with possession over you. 

  
  


He’d have to check that out later and definitely have a chat with Doggo that might end with dust on his newly preened clothes.

  
  


For now, he needs some more of that “relief” and this time he won’t go solo.

  
  


He popped back in the cave, puffing out his chest, his soul beaming excitedly and rumbling in his rib cage. Sans doesn’t know how long he could handle the smell, forcing himself not to pounce on you.

  
  


You looked up, focusing on the container in his claws. You shifted up, licking your lips. 

  
  


Sans granted you the food, which you happily snatched up and stuffed your face in. While you ate, he freed his soul. It bounced up and down and twirled itself towards you. It gleamed a bright red, misty magic flowing out freely before directing itself towards your chest while his soul remained inches from your face.

  
  


Sans smiled softly as he watched your eyes sparkle with awe, bits of meat sticking to your cheeks. 

  
  


“What’s it doing?” You asked, your eyes never leaving his soul.

  
  


“a courtship.” He answered simply. 

  
  


Warmth spread throughout your chest. Literally. The magic sparkly mist phased through your chest. It felt like the mist was latching itself onto something, wrapping all around it. You could feel everything, the warmth grew hot and a little unbearable but never painful.

  
  


The soul began pulling back, using the mist as tiny ropes. You panted, the heat and glow growing stronger. Finally, the soul gave one last strong tug and out phased a soul, the red mist tied around it. The mist dissipated, leaving what you soon discovered was your very own soul.

  
  


You gasped. The two souls stood still for a moment before Sans’ soul broke into a dance, trailing circles around your own soul. Your soul stood still, as if it were watching and judging. Not even a few seconds in did your own soul join in the dance. Now both were twirling around each other, releasing barely audible vibrations that sounded like two tiny humming whales. 

  
  


“you accepted me.” Sans whispered, his own eye-lights glowing with anticipation. “the courtship should be done.”

  
  


The moment both souls began to inch closer to each other, Sans cut his hand between them. His soul protested by wiggling in his grasp. Your own soul somehow seemed distressed and quickly retreated close to your chest, phasing back in soundly.

  
  


Sans grunted, shoving his soul back in his rib cage. 

  
  


“ha, that, uh, wasn’t supposed to happen,” Sans mumbled, self-consciously.

  
  


You glared at him, a bit alarmed. “You could have told me earlier!” Something buzzed inside your chest like it was your soul talking.

  
  


Sans leaned down and cooed, a deep rumble passing from his large chest to his non-existent throat. The sound covered you in gentle waves, your soul calming and your eyes half-lidded. It felt like you were in some sort of spell. Your heat, which you somehow ignored during the courtship, ten-folded into a fire spreading inside your cunt.

  
  


“Wuh-wait. What’s happ-happening?” You huffed. A small part of you hopelessly trying to get away from humping into your best friend (boyfriend?) was fleeting miserably while the hypnotized, expectory and larger part wanted to mate with the strong, suitable male. You kvery well what was happening, what you _ wanted _.

  
  


But it felt… wrong.

  
  


Sans crawled till he was above you, gently pushing your back against the bedsheets. Something about his gaze sent chills. “relax. i’m just trying to helping you.” His coos grew softer, as his teeth nuzzled your left cheek, both of your chests were touching and you could feel his ribs softly vibrating. 

  
  


You wonder how it would feel pressed against you. Your legs spread apart, attempting to wrap them around his middle. His size made it impossible but your crotch was coerced to his abdomen.

  
  


Jesus, what are you doing? The more you act out on these… urges, the more you actually began to _ want _ it. This is just terrible, so _ very, very, _terrible. 

  
  


….

  
  


Then why did it feel _ good? _

  
  


You dismissed it as the heat but now feelings were involved in this. You loved him but everything was moving too fast. 

  
  


He really shouldn’t be here.

  
  


“You-unf, you really shouldn’t be here. This isn’t a good idea Sans.” You hoped, _ begged _ that he surely would agreed, teleport out of here, and leave you to your sinful self. 

  
  


“this is good for you, you’ll see.” Sans pulled back his head before his long, flat tongue dropped out. He dragged it across your lips, leaving a red, translucent trail of saliva. It felt like less of a kiss between lovers and more of a dog licking its owner. 

  
  


Somehow, you didn’t mind. You began to grind up against him, bringing somewhat of a relief and feeling all the more terrible. Emotionally speaking. Physically speaking, you really couldn’t say the same. The small span of pleasure quickly ended when Sans pushed himself up. You growled unnaturally, gripping his loose shirt. He cooed some more and you let go, despite yourself. 

  
  


“Sans,” You headily demanded his attention, placing your heels strongly against his chest to keep him away (though you preferred that he would be _ closer _ ). “Sans, _ no _.”

  
  


He ignored you, his sharp-pointed claws grasped under your knees and lifted them up. Sans leaned down to align his face just above your throbbing center. His tongue dipped out, giving a long, languid lap to the round wet spot above your underwear. 

  
  


“Hah-ah!” You trembled, stifling a pathetic mewl. He encased his maw across your engorged cunt a couple of times before bringing out one of his long sharp claws and hooking it on the hem of the thin fabric. The underwear ripped away easily, leaving your puffy slit exposed. 

  
  


You tried your best to end this but even then, you realized that _ both _ of you couldn’t ignore how strong and controlling the heat was. After all, it was _ magic _.

  
  


Your core released the familiar sweet sugary syrup into the air, urging the humanoid skeleton monster to mount you and knot completely inside. For now, he had other ideas, besides, you don’t know how ‘big’ he’ll be.

  
  


He brought both hands to grip your behind and hold you in place, making sure you wouldn’t shift too much. You felt the first touch of his hot tongue drag itself up your slick labia, squeezing your eyes shut and whimpering. Sans was right. This did help and you wanted _ more _.

  
  


Sans watched you squirm with one eye open and a smirk. He pulled one hand away to paw desperately at his stiff, grunting impatiently. He took this chance to plunge his hot tongue inside. You choked, bringing, grabbing his head and clasping your fingers around the smooth, round surface. His tongue wiggled inside, struggling to fit before withdrawing back into his toothy maw. 

  
  


His broad, dull pointed fangs brought concern. It almost felt like he was going to clamp his jaws around your core but he only seemed to bring out his tongue again. He lapped away at your slick entrance a few more times, occasionally dipping his tongue inside and spreading walls apart and slurping and swallowing. He actively began flattening his tongue against your swollen clit, pressing harshly against it. You whimpered as your thighs reflectively latched onto his head.

  
  


You heard another coo reverberate off his chest, claws coming up to softly move your legs up. He scooped his tongue back in his maw, swiping it across his ivory canines. You panted, eyeing him and grunting. You tried to shove your crotch back to his teeth but he held you securely in place. Sans lowered his head just a few more centimeters and dunk his tongue fully inside you, plunging deeper than before. You lurched upwards and slammed a hand to your mouth, wincing.

  
  


This wasn’t even his dick, but his massive tongue brought pain. Sans dunk inside more, his sharp pointed teeth just barely touching your bare, sweat sheened skin. He breathed raggedly, struggling to fit his magic in completely until he felt a spongy little center. As soon as he pressed against it, you gritted your teeth and trembled, trying very hard not to squeak out a pathetic moan.

  
  


Sans pulled his tongue away swiftly before plunging back in, stroking your g-spot. He hummed lowly, only adding to the pleasure of it all. You felt tight around him, but he didn’t mind one bit. You needed to be prepared for his much larger cock, especially his knot that he planned to pop inside you.

  
  


Stars, he felt his own cock throb in his pants, every part of him demanding to mount and claim you, the smell of your heat only amplifying the instinctual desire. He subconsciously bucked forward into the empty space below him.

  
  


You tasted like nothing else, sweet like pudding but a thousand times better. He swirled against your walls until he felt you clamp harshly around him. 

  
  


You gasped and jolted as your orgasm gushed outwards, coating his tongue. Sans eagerly swallowed as much as he could, only adding to your pleasure. You fell limp and exhaled, turning your head and noticing your white-knuckled grip in your nest blankets. You took a small breather, which didn’t end when you felt Sans positioning himself above you till his chest smooshed your face and his pelvis aligned with yours.

  
  


His weight felt like a boulder, trapping you under him. And not to mention the sudden bulging warmth pressed fully against your wet entrance. You heard Sans’ breath hitch, quaking with need and jolting into you. His shorts were still on, so he only accomplished to shove his girth against you like a desperate, horned dog.

  
  


“hah-guh.” He rasped, tongue hanging out with a trail of drool dribbling down his maw. You felt squished, air forcefully leaving your lungs every time he rushed against you. 

  
  


With a frustrated growl, he pulled back and brought one claw out and quickly flung his shorts off, only it stopped at his ankles and went no more. He positioned himself back, his cock swaying back and forth with his hips.

  
  


And cripes, was he _ big _ . You weren’t sure how he could fit, let alone how it _ couldn’t _hurt. Terror wrapped around your soul and you attempted to push away. “You’re gonna kill me with that, Sans!”

  
  


“you’ll be fine, heats make _ everything _feel good.” He reassured with a slur, too dazed into wanting to breed. He covered you, arms placed on each side of you so you wouldn’t escape. His knee shifted up, forcing your thigh to travel with it and opening your legs as wide as possible. 

  
  


His heated cock slid fully on, your wet cunt lubricating him. He rutted up and down slowly, wanting to feel every part of you. Sans squeezed his eye sockets, intoxicated with how you _ felt _. This felt a million times better than his own hand. He rocked his hips for a good half minute, making sure his head would pass by your entrance and lather your slick up.

  
  


Oh, _ stars _ , he needed this. He was surprised he lasted this long but the wait was _ so _ worth it.

  
  


His head met your entrance one last time before he rolled his pelvis upwards, his head slowly popping inside and then halfway. He growled, your insides flexing against his width.

  
  


“(y-y/n). mmh.” He looked down at you, shakily laughing. You were wincing and you held your hands securely over your mouth. “do you see now? this helps.” He thrusted up, his massive shaft stretching your walls farther than you thought possible, but never painful. Your magic induced heat helped with that.

  
  


He felt the end base of his cock swell up into a knot. The top of it smacked against your sprawled, wet opening when he was finally, completely enveloped inside you. He panted breathlessly. “yes, ah, oh yes.” 

  
  


He wasted no time to roll his hips into a, granted unsteady pace, feeling your walls gush against him in every movement, his cock was pressed fully to your g-spot. 

  
  


He needed to breed you.

  
  


_ Now. _

  
  


The sooner the better.

  
  


You hid your face with both hands, gasping and choking with each thrust. You clutched his pelvis with your legs, seeking some sort of handle to help you ride this out. You manage to pummel into another glorious orgasm, screaming inwardly as you clawed at his shirt. 

  
  


Sans kept his pace, never letting up. Eyeing your bouncing body, wishing he could bend down and slobber at your neck without hurting and unnaturally bending his back. Because of the height difference, the entire position was awkward. He didn’t care. He just needed to speed things up a little. He bucked relentlessy, shifting one of his hands to your chest to hold you down. Sans gritted his teeth, concentrating. His thrusts grew sharper and faster till only his knot rolled and shivered, waiting patiently to enter. 

  
  


You felt his pointed claw tips dig into your sweater, piercing through the thick cloth and poking your skin. You winced, feeling something fleshy and bulbous rubbing just between your thighs. It felt like an oversized tennis ball. Then you realized it, Sans himself, was trying to shove it inside you. “S-Sans, ah!” From the pace he was going, it was hard to speak without sounding like driving over a road covered in speed bumps. You felt the beginning of his knot enter, spreading your folds apart. Sans grunted and moaned, his pelvis going completely still and ever so slowly moving between your legs. You gripped his hand pinning you, panting and wheezing from his heavy stature. 

  
  


“hah, oh _ fuck _.” Within a second, his knot popped fully inside and you wailed. 

  
  


“I-It hurts!” You kicked away harshly, trying to escape. 

  
  


Sans was yanked forward with you and whined, pain erupting through his crotch. “y-you gotta stay still.” His cock twitched happily, hot cum spurted out in globs and filled your womb.

  
  


You hoped your walls wouldn’t tear, you heard how painful it could be. 

  
  


Meanwhile, though in pain and anxious, Sans felt at peace with himself.

  
  


_ This is what he was looking for. _

  
  


He did his job.

**Notes for the Chapter:**

> Everything’s downhill from here.


	7. Roses Aflame

**Summary for the Chapter:**

> Sans fools himself into justifying his wrong doings. And you’re the victim of it all.

**Notes for the Chapter:**

> Hello Queens. Hope you’re all doing well and that the coming months bring peace for you. 
> 
> This story is finally up and back running. I’m not going to give up on this story, I’m determined to finish it. I know it’s been a while but I’m here to continue and finish what I started.
> 
> That being said, this story is on its way to becoming a dark fic, so warning to all my readers.
> 
> Also, holy smokes, my fic has over 9000 hits?! I honestly never thought it’d get past 5000 when I’d finish this. Thank you all for reading it. :)

Sans’ weight restrained any movement you attempted, proving difficult to breathe underneath. His massive knot anchored inside, repeatedly pumping his thick, sweltering seed into your ready womb. 

  
  


You pulled away, desperate to vacate this agony. Sans’ skull scrunched and he stumbled, his knees slipping across the nest to catch up with you. His groan morphed into a growl of frustration and irritation. 

  
  


“ **stop.** ” He demanded, voice low with warning. He bared his fangs, curling into an unimpressed scowl.

  
  


You stilled as you gaped at his sharp maw, flashing back to the time you first met him, his teeth ready to devour and rip apart. 

  
  


_But that was years ago._ _There is nothing to be afraid of now. _You desperately but poorly convinced yourself.

  
  


“Why didn’t you listen to me?” You pulled away again only to earn two heavy hands pinning you down with force. “I-I told you, no.” You hissed inwardly with pain, wincing as Sans rolled his hips slowly upwards, connecting both of your pelvises, skin to bone.

  
  


Sans, himself, felt too dazed and heated. His bones burning almost painfully, longing to be touched. He subconsciously lowered his whole chest on top of yours, latching his claws on your hands above your head, staring down with his tongue flapping out and drooling. 

  
  


You felt _ so _ good around him.

  
  


“Sans!” You grunted, the sudden weight making it difficult to breathe. Your hands flew up to push his face away. His drool covered your palm and fingers, slipping across his chin with little effort and almost cutting yourself when you skimmed dangerously close to his large, razor fangs.

  
  


This seemed to snap Sans out of his daze for a second before he began slowly opening and closing his jaws, staring down at you with tiny, crazed pinpricks focusing on your eyes.

  
  


No. Focusing on your  _ neck _ .

  
  


You whimpered and shrank inwardly to the nest, dropping your hands to shield your neck. 

  
  


Sans maw snapped closed, his perma-smile quivering. He proceeded to grind his teeth together harshly.

  
  


You knew. 

  
  


Somehow you knew he wanted to sink his teeth into your neck. 

  
  


You desperately searched for a way to distract him. 

  
  


“You’re hurting me.” You whimpered, face flush with shame.

  
  


Sans blinked, his face unreadable. 

  
  


You continued, wondering if you had his attention. 

  
  


“Please, Sans, i-it hurts. I think I muh-might rip.” Your breathing quickened as you felt the weight of his rib cage slowly disappear and you could breathe better. “...Sans?”

  
  


The skeleton didn’t respond. Rather, he placed his hand to your chest, making sure his boney palm rested completely against your bosom, pressing against the top of your breasts. A familiar warmth flared inside. His hand became coated with red misty magic, slowly lighting up the dark cave. The magic phased through your chest, scooping out your bright beating soul.

  
  


You fixated a suspicious look to Sans, knowing just how frequently impulsive and lackadaisical he acted. 

  
  


Sans held your floating soul in his massive hand, admiring its glistening surface. In a second he brought out his tongue, his canines glinting in the casted light, scraping just above the top of your quivering soul. 

  
  


It was almost as if you could feel his hot breath traveling across the surface of your soul to your skin, warming you up until it burned. Both you and your soul shivering in unison. Your hands scrambled to the rim of his shirt, clutching for purchase. You glared at him with pure distrust but decided to say nothing. 

  
  


He wouldn’t listen to you anyway.

  
  


He gave a long lap to the surface, glancing down lustfully at your gaze, matching the fire burning deep inside. You cried out, white knuckling your hands around his thin shirt material harshly.

  
  


Oh, god! 

  
  


Your back arched and your legs clamped around his pelvic bone. Drool dribbled down from your chapped lips. 

  
  


Sans began rolling his hips up gently. Even with his slow pace, the girth of his knot alone stretched you apart painfully. As Sans kept lapping away at your soul, the pain ebbed slowly.

  
  


Sans seemed to take notice almost immediately, lifting his skull upwards and inhaling your powerful scent around him. How he was able to smell anything at all was pure mystery to you. Sans shivered as if your scent crawled all over his bones, seeped inside his chest, and ripped into his own soul.

  
  


The rolling of his hips quickened as he resumed his assault on your soul, magic dripping into his palm and down his wrist and arm. 

  
  


“Hah!” You squeaked out a moan as you thrust your hips to meet his snail-like pace. Your cunt ached to be harshly thrusted within, your heat filling your head with images of being pinned down and mated. Shamefully, you squeezed your eyes shut till you saw white. You bucked back into him, mewling his name out. “Sah-Sans!”

  
  


Sans leaned over, his back jutting out awkwardly. His teeth press up against your sweat sheeted neck, breath hot and tempted against your jugular. Without thinking, you tilt your neck, granting access.

  
  


Sans eye lights gaze at you with longing. His tongue comes out and licks gingerly to your neck. He lets his labored moans fall across your face. He smells like fresh meat, pine, fire, and spice.

  
  


His knot bulges inside your slick entrance, keeping him locked in place. Thrusting with his knot locking him in place proves to give little stimulation. You buck into Sans, getting more desperate. His cock spurts more thick strings, adding to the forming bright red bulge of your uterus. You wonder how long monsters can cum when knotted. 

  
  


—-

  
  


Sans feels a wave of his own forming heat overtake him when he surveys the naked female beneath him,  _ his _ human. Her breasts pressed flush against his ribs, her legs wrapped around his middle, her confused hands scramble to either clutch his tattered shirt or his back. 

  
  


Stars, her heat was sending him into a semi-heat that felt just as powerful as a real one.

  
  


If only you knew just how hard he was clamping his jaws shut, this force could shatter a buffalos skull into pieces. His gaze kept blurring, he found it hard  _ not _ to stare at your neck. 

  
  


You looked so… inviting.

  
  


But he couldn’t mark you, not just yet. He needed a true bond. One so pure and ripe. He needed more time.

  
  


A cub should do it.

  
  


His spine felt aflame, his knot unrelenting. 

  
  


He decided to leave your pulsing soul be. The entire purpose of bringing it out was to ebb your pain, which he was sure he succeeded. Watching you writhe in torment made him feel unbearably guilty, he just wanted you to feel  _ good _ .

  
  


He shifts his hips until he’s upright. 

  
  


Human males impregnate human females with just a few spurts and Sans is sure that he came  _ much _ more than that.

  
  


Sans gingerly rolled his hips up, surveying his human’s reactions. She looked completely exhausted, depleted from her energy. Her eyes stared into open space, round and dull and tired. Her left mouth half open with slow, heavy breathing. Her grip loosened around his shirt.

  
  


Sans leaned down to nuzzle her cheek, a deep purr reverberating off his ribs, attempting to calm his would-be mate.

  
  


He felt her soft palm run up his cheekbone and stay there. Sans turned to see the human’s gaze focused on him again.

  
  


You looked sad….

  
  


Sans scrambled to find a way to cheer you up, make you feel better. 

  
  


You can’t be upset with him, you just can’t. You’re supposed to be happy about this. He helped, didn’t he?

  
  


You should be grateful. 

  
  


“do you… feel better?” His soul fluttered when you finally, slowly, looked up at him. 

  
  


Her eyes focused again, this time sharper and unforgiving. 

  
  


“Do  _ you _ feel better?” She outright spat.

  
  


Sans shrunk down, he didn’t know whether to growl at her and keep her pinned down or cower into her chest like a frightened pup.

  
  


“i-i helped you. i did what i was supposed to do, i protected you.” The monster struggled to find his words, scolding himself for becoming so feeble over a human.

  
  


“You fucked me, Sans. How does fucking me even begin to help?” She began to find her bearings, looking around the cave. “The only danger here is  _ you _ .”

  
  


“no, no! tha-that’s not true. i helped your heat, i did what i was supposed to do.” He repeated.

  
  


“Are you trying to convince me or yourself?”

  
  


Sans tried to speak, but for his life, he couldn’t think of anything good to say. His knot twitched, still not ready to slip away without hurting both of them.

  
  


“... your heat is too strong.”

  
  


“And that’s my fault?” 

  
  


Sans shook his head. “no, of course not, but it could’ve gone worse if I wasn’t here.” Sans paused. “There was a monster outside, roaming around.”

  
  


You blinked slowly, going rigid. “I thought all monsters had traveled to the surface by now. Well, not including your brother.”

  
  


“a former royal guard. he must’ve been down here to collect some stuff, happens a lot with monsters.” Monsters liked to come and go from their former house to their new one. Usually to collect their remaining things or to reminisce about their past.

  
  


Doggo must’ve been here on behalf of Queen orders too. There was still a lot of useful stuff to be used down here. But Doggo picked up something else, apparently. 

  
  


“You said monsters can’t control themselves during a heat….” You looked him over, giving a sad look. Sans quickly dismissed your glance. “Wouldn’t I be safer… somewhere else?”

  
  


“ ** _no_ ** _ . _ ” Sans replied all too quickly. “i mean, the surface is different now, remember? no human can roam around freely without the danger of a monster nearby.”

  
  


“I roam freely around here all the time.”

  
  


“you know what i mean. you’ll be killed.”

  
  


You sighed and laid back, exhausted and chewing your lip in contemplation. You suddenly flushed darker and your scent thickened around the air.

  
  


Sans being so close to you, grunted and sucked air harshly through his teeth. His energy became utterly depleted, his hips quivering in exhaustion to stay up. His magic felt sensitive and overwhelmed.

  
  


“How long is this gonna last?” You inquired embarrassingly. You turned away to avoid looking at him, sweat beading at your forehead.

  
  


“as long as it needs to.” Sans bent down to lick away the sweat.

  
  


“Mm.” You hummed drowsily, eyes fluttering closed. You quickly drifted into slumber, to Sans’ surprise.

  
  


Humans can sleep for hours and still be tired. Sans kept quiet as he watched you fully slip away into sleep.

  
  


He wondered how in the stars, he would ever begin to explain the life forming inside you. It wouldn’t take long for the half monster half human cub to develop, they only took a quarter amount of time a pure human cub would take to be born.

  
  


He didn’t want to rush any of this with you, but your completely random heat was too hard to ignore.

  
  


He wanted more time, he would’ve liked his confession not to be forced out so quickly. 

  
  


Sans, if he could ever be honest with himself, didn’t feel guilty mating you. 

  
  


He truly didn’t. 

  
  


He imagines you in the near future, belly round with his cub. Safe and secure close to him. 

  
  


He imagines ravaging his future mate, holding her down and claiming her. 

  
  
  


He imagines bonding both of your souls to become one in a beautiful private ceremony, becoming soulmates forever.

  
  


Sans noticed he stopped cumming inside his would-be mate and she didn’t feel so tight around him anymore either.

  
  


Adjusting his claw hands, he moaned as he slowly pulled out of her with a squelching pop. Glowing red cum spilled from her sensitive folds, ruining the sheets under them. 

  
  


The skeleton grunted, completely spent. He manifested his dick away, watching it dissipate into air. He was surprised it didn’t wake her

  
  


He moves her over to a cleaner spot of the nest, wrapping blankets around her as she continues sleeping. His attention was caught onto her neck again as he pulled the blanket over her.

  
  


Something inside him screams to sink his canines into the soft, delicate flesh. He almost felt dizzy off the instinct to mate her again since her heat scent remained in the air.

  
  


He had to resist forming his magic again for her, he needed to find another place where she could stay. 

  
  


You can’t stay here. 

  
  


He needs to hurry before Doggo comes back, or worse, another boss monster comes. 

  
  


He gives a long, loving look at your limp form before disappearing away.

**Notes for the Chapter:**

> Will edit later. It’s not as long as the other chapters but screw it, future chapters will have more as they are created.
> 
> On a side note, I am once again asking you to join me on tumblr, if you’re interested. I’ll be posting chapter updates, answer questions, make mini stories, and create art there.
> 
> https://www.tumblr.com/blog/candlewaxwrites


End file.
